The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 27, 1999
Filed:
May. 01, 1996
Hitachi, Ltd., Tokyo, JP;
Abstract
Light from a light source is fed to a sensing probe through a polarization plane-reserving fiber, and is split into two light beams, that is, a reference beam and a measurement beam. The reference beam is passed through a reference medium, and the measurement beam is passed through a pressure-sensitive medium, which may be in the form of gas. Then, the reference beam and the measurement beam are fed to a light-receiving portion via the polarization plane-reserving fiber, and are converted into electrical signals. The electrical signals are inputted into a signal processing portion, and the optical path length difference between the reference and measurement beams, passed through their respective mediums, is determined, and the pressure of the pressure-sensitive medium is detected from this optical path length difference.